Booster vaccines reduced the risk of COVID 19–related hospitalisation and death, according to a new study of over 3 million adults who had the autumn 2022 vaccine in England. The research led by the universities of Bristol and Oxford, provides further evidence of the effectiveness of booster vaccination against COVID-19.
The study, published in Vaccine today (18 February), also found that this effectiveness was similar for Moderna (BA.1 mRNA-1273) and Pfizer-BioNTech (BA.1 BNT162b2) booster vaccines, but protection declined over time.
Previous work has shown the initial COVID-19 vaccination was effective in reducing the risk of hospitalisation and death due to COVID-19. This latest research, carried out at the National Institute for Health and Care Research (NIHR) Bristol Biomedical Research Centre (BRC), looked at the impact of giving people a booster vaccine.
The team investigated the effectiveness of Moderna and Pfizer-BioNTech booster vaccines administered during the autumn 2022 booster campaign in England for previously vaccinated people age 50 or over.
The NHS England approved study analysed linked GP and hospital records available within the OpenSAFELY research platform. The team compared 3,464,877 adults eligible for booster vaccination during the autumn 2022 COVID-19 vaccine rollout with the same number of unboosted people.
They matched them with people who were similar in terms of age, date of last COVID-19 vaccine dose, brand of prior vaccination, clinical vulnerability and geographical region. The researchers then followed these people up for nearly a year and tracked hospitalisation and death due to COVID-19.
Across 2.5 million people followed up over a year, the study recorded 14,436 COVID‑19 hospitalisations, 1,152 COVID‑19 deaths, 32,184 non‑COVID‑19 deaths and 52,758 fractures.
The study found boosted individuals had much lower 350‑day risks of COVID‑19 hospitalisation (3.78 vs 6.81 per 1,000) and death (0.29 vs 0.61 per 1,000). Boosters halved the risks of COVID‑19 hospitalisation and death. Protection waned over time, strongest in the first 70 days. Moderna and Pfizer‑BioNTech boosters performed similarly for COVID‑19 outcomes, though non‑COVID‑19 mortality was slightly higher in the mRNA‑1273 group.
The study also assessed the relationship between booster vaccination and fracture, an outcome not considered likely to be causally related. A small reduction in fracture risk was found for boosted individuals. This suggests that not all confounders (common causes of booster vaccinations and outcomes) were accounted for, but the much smaller effect for fracture is reassuring for the validity of the study’s conclusions.
Dr Paul Madley-Dowd, Research Fellow in Medical Statistics and Health Data Science, and corresponding author at University of Bristol, said: “Our findings reinforce the importance of booster vaccination against COVID-19 among people over 50 years old.
“The study also provides further evidence that COVID-19 booster vaccinations reduced the risk of hospitalisation and death.”
This work was funded by NHS England; Wellcome Trust; MRC; NIHR; NIHR Bristol BRC; OpenSAFELY; and the Bennett Institute for Applied Data Science.
Paper
‘Effectiveness of bivalent BA.1 mRNA booster vaccines during the autumn 2022 COVID-19 booster programme in adults aged 50+ in England: observational matched cohort study using OpenSAFELY’ by Paul Madley-Dowd et al. in Vaccine
Further information
About the National Institute for Health and Care Research (NIHR)
The mission of the National Institute for Health and Care Research (NIHR) is to improve the health and wealth of the nation through research. It does this by:
- Funding high quality, timely research that benefits the NHS, public health and social care;
- Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services;
- Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research;
- Attracting, training and supporting the best researchers to tackle complex health and social care challenges;
- Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system;
- Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.
NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK international development funding from the UK government.
About the National Institute for Health and Care Research Bristol Biomedical Research Centre (NIHR Bristol BRC)
NIHR Bristol Biomedical Research Centre’s (Bristol BRC) innovative biomedical research takes science from the laboratory bench or computer and develops it into new drugs, treatments and health advice. It focuses on early phase translational research and experimental medicine that aims to improve mental and respiratory health, optimise physical activity, nutrition and weight maintenance in the population, and introduce new surgical and orthopaedic interventions safely and ethically.
Bristol BRC draws on Bristol’s expertise in developing interventions to improve the health of patients and the public. Its world-leading scientists use detailed genetic and molecular data to understand causes of disease. They also evaluate new surgical procedures and analyse large-scale datasets from records collected during routine NHS care. Bristol BRC is unique among the NIHR’s 20 BRCs across England, thanks to its expertise in ground-breaking population health research.
